Hi.
I need some help on getting projective texturing working properly. Fixed
Functionality is no problem however in GLSL am having a number of
problems. I can get the texture onto my quad however I can't position it
correctly. The texture appears basically in the Middle of my plane -
however I require it to be scaled and positioned anywhere - in this
case it will be the wake of a ship.
I've included the basic setup of my code - with relevant sections.
Hopefully someone may see something I'm missing.
Kind Regards
Paul
SETTING UP
///////////////////////////////////////////////////////////////////
_group = new osg::Group;
osg::Vec3 position(1500.0f,1500.0f,0.0f);
osg::Vec3 direction( 0.0f,0.0f,-1.0f);
osg::Vec3 up(0.0f,1.0f,0.0f);
//create the _camera
_camera = new osg::Camera;
_camera->setClearMask(GL_DEPTH_BUFFER_BIT);
_camera->setClearColor(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
_camera->setComputeNearFarMode(osg::Camera::DO_NOT_COMPUTE_NEAR_FAR);
// set viewport
_camera->setViewport(0,0,256,256);
// set the _camera to render before the main _camera.
_camera->setRenderOrder(osg::Camera::PRE_RENDER);
// tell the _camera to use OpenGL frame buffer object where
supported.
_camera->setRenderTargetImplementation(osg::Camera::FRAME_BUFFER_OBJECT);
// attach the texture and use it as the color buffer.
_camera->attach(osg::Camera::DEPTH_BUFFER, _projectionTexture);
// add subgraph to render
//_camera->addChild(_nodeprojectedonto.get());
_group->addChild(_camera);
osg::StateSet* stateset = _group->getOrCreateStateSet();
osg::Vec4 centerColour(0.5f,0.5f,0.5f,1.0f);
osg::Vec4 borderColour(1.0f,1.0f,1.0f,1.0f);
// set up forest _projectionTexture
_projectionTexture = new osg::Texture2D();
_projectionTexture->setImage(createForestImage(centerColour, 64));
_projectionTexture->setBorderColor(osg::Vec4(borderColour));
_projectionTexture->setWrap(osg::Texture::WRAP_S,osg::Texture::CLAMP_TO_BORDER);
_projectionTexture->setWrap(osg::Texture::WRAP_T,osg::Texture::CLAMP_TO_BORDER);
_projectionTexture->setWrap(osg::Texture::WRAP_R,osg::Texture::CLAMP_TO_BORDER);
stateset->setTextureAttributeAndModes(textureUnit,
_projectionTexture, osg::StateAttribute::ON); //TEXUNIT2
// set up tex gens
stateset->setTextureMode(textureUnit, GL_TEXTURE_GEN_S,
osg::StateAttribute::ON);
stateset->setTextureMode(textureUnit, GL_TEXTURE_GEN_T,
osg::StateAttribute::ON);
stateset->setTextureMode(textureUnit, GL_TEXTURE_GEN_R,
osg::StateAttribute::ON);
stateset->setTextureMode(textureUnit, GL_TEXTURE_GEN_Q,
osg::StateAttribute::ON);
osg::TexGenNode* _texgenNode = new osg::TexGenNode;
_texgenNode->setTextureUnit(textureUnit); //TEXUNIT2
osg::TexGen* texgen = _texgenNode->getTexGen();
texgen->setMode(osg::TexGen::EYE_LINEAR );/
_group->addChild(_texgenNode);
texGenMatUniform->setUpdateCallback(new
TexGenUpdateCallback(_viewer,projection->getTexGenNode()));
stateset->addUniform( texGenMatUniform);
//set a wake texture
stateset->setTextureAttributeAndModes(TEXUNIT2,
projection->getTexture(),osg::StateAttribute::ON);
stateset->addUniform( new osg::Uniform("PROJECTION",TEXUNIT2) );
CALLBACK
///////////////////////////////////////////////////////////////////
class TexGenUpdateCallback: public osg::Uniform::Callback
{
public:
TexGenUpdateCallback(osg::ref_ptr<osgViewer::Viewer>
_viewer,osg::TexGenNode* texgenNode) : viewer(_viewer),
_texgenNode(texgenNode){}
virtual void operator() ( osg::Uniform* uniform,
osg::NodeVisitor* nv )
{
if( _enabled )
{
//Camera position
//osg::Matrix MVPT =
(viewer->getCamera()->getProjectionMatrix() *
viewer->getCamera()->getViewMatrix() );
//_texgenNode->getTexGen()->setMode(osg::TexGen::EYE_LINEAR);
//_texgenNode->getTexGen()->setPlanesFromMatrix(MVPT);
// compute the matrix which takes a vertex from local coords
into
tex coords
// will use this later to specify osg::TexGen..
osg::Matrix MVP = viewer->getCamera()->getViewMatrix()
*
viewer->getCamera()->getProjectionMatrix();
osg::Matrix MVPT = MVP *
osg::Matrix::translate(1.0,1.0,1.0) * osg::Matrix::scale(1.0,1.0,1.0);
_texgenNode->getTexGen()->setMode(osg::TexGen::EYE_LINEAR);
_texgenNode->getTexGen()->setPlanesFromMatrix(MVPT);
uniform->set(MVPT);
//std::cerr<<" TexGenUpdateCallback "<<std::endl;
}
}
private:
bool _enabled;
float angle;
osg::ref_ptr<osgViewer::Viewer> viewer;
osg::TexGenNode* _texgenNode;
};
VERTEX SHADER
//////////////////////////////////////////////////////////////////////
vec4 ecPosition = gl_Vertex * gl_ModelViewMatrix;
gl_TexCoord[0].s = dot(ecPosition, gl_EyePlaneS[0]) ;
gl_TexCoord[0].t = dot(ecPosition, gl_EyePlaneT[0]) ;
gl_TexCoord[0].p = dot(ecPosition, gl_EyePlaneR[0]);
gl_TexCoord[0].q = 1.0;
FRAGMENT SHADER
//////////////////////////////////////////////////////////////////////
vec4 ProjMapColor = texture2DProj(PROJECTION, gl_TexCoord[0]);
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